1. Field of the Invention
This invention relates to a display control apparatus and a display control method, and more particularly to a display control apparatus and a display control method suitable for use where display of a display unit is updated by updating image data placed in a back buffer into a front buffer in a VRAM (Video Random Access Memory).
2. Description of the Related Art
Drawing of an image on a display unit is performed such that image data are drawn in a buffer provided in a VRAM and the stored substance of the VARM is reflected on the display unit. Accordingly, if the timing at which the substance of the VRAM is reflected at an inappropriate timing, then an incomplete image corresponding to image data during drawing in the VRAM may be displayed on the display unit.
An exemplary apparatus which prevents such a situation as described above is disclosed, for example, in Japanese Patent Laid-Open No. Hei 8-50659 and is shown in FIG. 1. Referring to FIG. 1, a first buffer 2 and a second buffer 3 of an equal size are provided in a VRAM 1. One of the first and second buffers 2 and 3 is used for drawing of image data while the other is used for reflection on a display unit 4. Further, the uses of the first and second buffers 2 and 3 are changed over alternately.
Also another apparatus is known wherein a front buffer is provided in a VRAM while a back buffer is provided in a main memory. The back buffer is used for drawing of image data while the front buffer is used for reflection on a display unit, and the stored substance of the back buffer is transferred rapidly to the front buffer.